Grate.



A. B. GOATES.

GRATE.

APPLICATION FILED APB. 15, 1913.

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@140cm/cola i ED STAS PATE OFFlCE;

ARCH B; COA'I'ES, OF,ELLSWORTH, KANSAS, ASSIGNOR, BY DIRECT SIGN'MENTS,TO,ECON01VIY FORCED DRAFT SLACK BURNER COMPANY, 0F

WORTH, KANSAS.

.AND MESNE AS- ELLS- GRATE.

Specification of Letters Patent.

Patented June 30, 1914.

Application lecl April 15, 1913. Serial No. 761,378.

To all whom it may concern Be it known that l, ARCH B. CoA'rEs, citizenof the United States, residing at Ellsworth, in the county of Ellsworthand State of Kansas, have invented certain new and useful Improvementsin Gratos, of which the following is a specification.

My invention relates to an improved grate construction and moreparticularly a grate for steam boilers and has for its primary objectthe provision of a grate which will insure a more complete combustion ofthe fuel and which will consequently cause a considerable saving in thecost of fuel.

A further object of my invention is to provide a grate including aplurality of grate bars positioned one immediately adjacent another withthe space between the bars filled with asbestos or other suitablepacking, the grate in effect forming a continuous floor for thereception of the fuel, thus preventing all waste, due to the passage offine pieces of coal or the like through the spaces now left betweengrate bars in the usual grate constructions.

A further object of my invention is to provide a hollow grate barhavingdraft openings in its upper face and a normally closed door at oneend, and to provide a grate construction embodyi g said bars wherein airunder pressure is forced into the grate bars and through the draftopenings to the bed of the fire. And a still further object of myinvention is to so construct the individual grate bars that the portionsof said bars having the draft openings and upon which the bed of firerests may be removed from the body of the grate bars and replaced incase they become burned out, broken or otherwise injured.

With these and other objects in view, my invention will be more fullydescribed, illustrated in the accompanying drawings, and thenspecifically pointed out in the claims which are attached to and form apart of this application.

In the drawings: Figure 1 is a sectional viewI of a conventional form ofboiler and boiler furnace, showing the application of a grateconstructed in accordance with my present invention; Fig. 2 is afragmentary top lan view of the grate; F1g. 3 1s a lon- Oitudinalsectional view on the line 3--3 of n u l l l Fig. 2; Fig. 4 is atransverse sectional view l on the line 4-4 of Fig. 3, looking in thedirection of the arrows; Fig. 5 is a perspective view of one of thegrate bars employed in the grate shown in Figs. 1 to 4 inclusive of thedrawings.

orresponding and like parts are referred to in the followin descriptionand indicated in all the views of the drawings by the same l referencecharacters.

To insure a clearer understanding of the construction and operation ofmy improved grate l have illustrated the same in connection with aboiler and boiler furnace of conventional type in which 10 indicates the1 11 the bridge wall,

front wall of the furnace, 1Q the floor or l the fire box. The frontwall is provided with the usual door openings and doors permittingcominunication with the ash pit and tire box, the door to the fire boxbeing indicated by the numeral 15 and being hinged to swing into closedposition against an inverted U- y shaped door frame 16. The outer end ofl the grate, indicated as a whole by the numeral 17, forms the lowerportion `of the door casing for the door 15 and the grate is supportedintermediate its length by a transverse supporting bar 18 and at itsrear end by the bridge wall. l Referring more specifically to Figs. 2 to5 inclusive of the drawings, it will be noted that the grate is made upof a plurality of separate and unconnected grate bars each indicated asa whole by the numeral 19. AEach of these grate bars consists of a basei 9.0, vertical side walls 21 and bridge meml bers Q2 and 23 connectingthe end portions y of the side walls, all of said parts being cast orotherwise integrally formed. It will be noted that at the outer end ofthe grate bar the side walls are somewhat higher than throughout theremainder of their length l and that as a consequence the bridge memberat said end of `the bar is elevated above the main body of the bar. Atthe extreme outer end however, the grate bar as a whole is reduced tonormal size to provide an angular seat 24 against which the door 15 ofthe fire box closes.

A draft plate closes the top of the grate bar between the bridgemembers, said draft plate comprising a section 25 extending parallelwith the base 20 from the bridge membase, 13 the ash pit an eol ber 22to a point adjacent the bridge member 23 and an inclined section 26resting on the side walls between the rear end of said latter bridgemember and the forward end of the section 25. The draft plate is securedto the body of the grate bar proper by bolts 27 passed through the draftplate and the side walls of the grate bar and secured in place by nuts28, the heads of the bolts being countersunk in the upper face of thedraft plate. It will therefore be apparent that each grate bar is invfact tubular and unobstructed throughout its length, being openl at bothends.

The longitudinal edges of the base 20 of each grate bar are extendedsomewhat to provide spacer flanges 29, thepurpose of which will` behereinafter explained and the draft plate is provided with a pluralityof draft openings in the form of narrow, elongated, unconnected slots30. These slots may be arranged in any suitable position with respect toeach other although the herringbone arrangement illustrated in thedrawings is preferred. Each of the tubular grate bars thus formed inprovided at its` Outer end with a hingedl door or closure 3l which ispreferably air tight in its construction andy in buildingup a grate fromthese grate bars the outer ends of thebars are supported in` the`position usually occupied by the lower portion of the door casing insuch a manner that the door of the lire box will close against the doorseat 24 formed by the bars while the rear endsy of4 the grate bars arepassed into and supported by the bridge wall. The bars are mounted onebeside the other with the spacer flanges of one bearing against thespacer flanges of the. adjacent bars to space the body portions of thebars a slight distance from each other to allow for expansion of themetal when heated. The spacev thus formed between the upper portions ofthe grate bars is filled by a` packing 32 of asbestos wool or othersuitable heat resisting material which willv prevent tle accumulation ofashes and the like between the bars and which, will at the same timepermit the bars to expand. In employing' this type of grate constructionthe bridge wall of the furnace is of hollow construction toprovide anair chamber 33 communicating with the grate bars which, project by theirrear ends into this chamber. This chamber should be formed air tightandan air supply pipe 34 leads from this chamber to any suitable sourceVof compressed air supply such as a blower, conventionally shown at 35.

It will be apparent that when the blower is driven air will be forced;into, the air chamber 35 and from the chamber into the tubular gratebars passing from the grate bars through the draft openings 30 in thedraft plates and so directly to the bed of the tire providing aneflicient forced draft, the strength of which may be readily governed bysuitable adjustment of the blower. lit will of course be understood'that in use, the doors 3l' of all the grate bars will be closed and thatall air passing into the grate bars will therefore pass through the bedof fuel contained upon the grate bars. The draft openings 30 are sonarrow that very little ash will fall through, but it will be apparentthat the interior of the draft bars may be readily cleaned out at anytime merely by opening the doors 3l when the air from the blower willpass directly through the draft bars, blowing out any ashes or otherforeign matter contained therein.

The grate bars may be made in various sizes and proportions toy suit thetype of fire box in which they are to. be used and may of course besupportedy in any suitable manner in the fire box.

The type of grate construction above described will, greatly increasethe efficiency and capacity of boilers as it will burn more coal to' thesquare foot of grate surface than is possible. with grates now in use,due to the forced draft provided and to the, fact that this draft may bereadilyl regulated and thus kept within, the limits of capacity of theiiues and stack of the furnace. As the draft plates are formedseparately from the rest of the grate bars` they may be removed andreplaced if broken, burned out or otherwise damaged. Because of thisforced draft there are but few ashes left and practically no clinkers bereadily cleaned out. for this reason. Furthermore, each grate bar beingentirely separate and independent of the others is perfectly free toexpand and in addition lcan be readily removed for repairs withoutnecessitating the removal of the other grate ars.

lt will of course be understood that various changes, within the scopeof the appended claims, may at anytime be made in the construction of;the individual grate bars. or in the manner of assembling the same toforma complete grate, without in the slightest degree departing from theSpirit of my invention.

Having thus described the invention, what is claimed as new is:

l. In a grate construction, a grate bar including a base, sidewalls andbridge members connecting the end portionsof the side walls, all of saidparts being integrally formed, andv draft platesconnecting theintermediate portions of the side walls and provided with draftopenings, and detachable securingy devices inserted. through thedraft-plate into and through the side walls,

2.; A hollow grate bar comprisinoa a base, side walls rising therefromthrougl'iouty the length of 'thesame,and bridge members con and. thelires may necting the upper edges of' the side walls at the front andrear ends of the same, t-he front bridge member being stepped at itsfront end to form a seat for the fire-box door.

3. A hollow grate bar comprising a continuous plane uninterrupted base,side walls rising from the base, said walls being higher at their frontends than at their rear ends, bridge members connecting the tops of' theside walls at the front and rear ends of the same, and a draft placesecured upon the upper edges of the side walls and provided with aplurality of draft openings, said draft plate comprising a sectionextending` from the rear bridge member parallel with the base and asecond section extending from the front end of the first-mentionedsection upwardly and forwardly to the front bridge member.

4:. In a grate construction, the combination of a plurality of hollowgrate bars having laterally directed flanges and provided in their upperwalls with draft openings, said grate bars being positioned so that theflanges of' one bar bear against the flanges of the adjacent bars tospace the same apart, and a packing of heat resisting materialpositioned between the bodies of the bars and restin upon the flanges.

5. ign

a grate construction, the combinaopies of this patent may be obtainedfor ve cents each,

hollow grate bars having laterally directed flanges and provided intheir upper walls with draft openin s, said grate bars being positionedso that t e flanges of one bar bear against the flanges of' the adjacentbars to space the same apart, and a packing of asbestos filling theentire space between the bars and supported directly by said fianges.

6. In a grate construction, the c0mbination with supports for a grate,of a plurality of hollow grate bars positioned upon the supports, saidbars being rectangular in cross section and having laterally directedspacer flanges along their lover edges to space their body portionsapart, the spacer flanges of each bar bearing against the spacer flangesof adjacent bars, a packing of asbestos filling the entire space betweenthe grate bars and resting directly on the spacer flanges, said gratebars being formed in their upper wall with draft openings, and aswinging closure for the front end of each grate bar.

In testimony whereof' I aliX my signature in presence of two witnesses.

ARCH B. COATES. [n s] Witnesses:

ELDEN It. SHAW, W. R. Snavnn.

tion of a plurality of by addressing the Commissioner of Patents.`

Washington, D. G.

